EP2704811A1 - Filtering apparatus - Google Patents

Abstract

A filtering apparatus with a plurality of filtering elements (11) which can be accommodated in a filter housing (1) having a filter inlet (7) for fluid to be filtered and a filter outlet (9) for the filtered fluid, wherein during the filtration operation, at least one of the filtering elements (11) can be back-flushed by means of a back-flushing device (45, 49) in order to dedust the effective filtering surface of said filtering element, the back-flushing device comprising a pressure control device (19) for assisting the back-flushing operation, is characterized in that the pressure control device comprises a hydraulic accumulator (19), the one fluid chamber (47) of which can be filled during the filtration operation with a quantity of dedusted fluid and can be connected for a back-flushing operation via a back-flushing guide (45) to the clean side (29) of the filtering element (11) to be dedusted, and in that, for a back-flushing operation, a further fluid chamber (48) of the hydraulic accumulator (19) can be subjected to a gas pressure in order, by means of a resultant movement of the separating element (59) of the hydraulic accumulator (19), to at least partially again dispense the filling amount of the dedusted fluid for the back-flushing operation from the first fluid chamber (47).

Description

 filter means

The invention relates to a filter device with a plurality of filter elements, which are accommodated in a filter housing with a filter inlet for fluid to be filtered and a filter outlet for the filtered fluid, wherein during the filtration process at least one of the filter elements for cleaning its effective filter surface by means of a backwashing is backwashable, which includes a pressure control device to support the backwashing.

A generic filter device is disclosed in DE 10 2007 054 737 A1. Such a filtering device allows a continuous filtration operation, wherein successively filter elements to be regenerated, are backwashed, while the filtration is continued over the remaining filter elements, so that the filtration operation is interrupted at any time.

In the known filter device, the backwashing process does not take place exclusively in such a way that the system pressure prevailing in the filter device allows a partial flow of the filter to flow through the filter element to be cleaned in the reverse direction in order to detach and remove the dirt from the element, but instead that, in an effort to remove even more stubborn soils can, by means of a pressure control device to the backwashed filter element, a negative pressure is generated. Therefore, not only is the system pressure effective for the backwashing, but a higher pressure gradient is available under pressure control to remove soiling.

In the known filter device, the pressure control device has a shut-off element, by means of which the fluid connection between the fluid flowing into the filter housing and the respective filter element to be backwashed can be blocked for a respective backwashing process. As a result, there is a flow interruption in the fluid flow entering the filter element before the backwashing process, so that the flow velocity prevailing during the shut-off process produces a suction effect as a flow-dynamic effect.

As a result, not only the system pressure is available for the return flow of filtrate on the clean side of the relevant filter element, but the return flow of filtrate is enhanced by the Nachsaugwirkung, which is due to the dynamic effect available, resulting from the blocking of the flow flows in from the dirty side.

However, the size of the hydrodynamic effect achieved by the shut-off process is dependent on the flow velocity and therefore limited accordingly. In applications where persistent contamination is expected to be difficult to remove from the filter surface, there is a risk that the hydrodynamically assisted backwash effect will not be fully satisfactory.

In view of this problem, the invention has the object to provide a filter device available, in which a supported by pressure control, particularly effective backwashing effect can be achieved. According to the invention this object is achieved by a filter device having the features of claim 1 in its entirety.

A significant feature of the invention is therefore that the pressure control device includes a hydraulic accumulator whose fluid chamber, while the device operates in filtration mode, can be filled with a quantity of cleaned fluid and for a backwashing process via a backwash guide with the clean side of each abzusini- ing Filter element is connectable. When pressure is applied to the further fluid chamber of the hydraulic accumulator, the movement of the separating element of the hydraulic accumulator caused thereby results in an ejection of the filling quantity of the fluid, which passes as flushing fluid via the backwash guide to the filter element to be cleaned. By choosing the amount of gas pressure that is used in the hydraulic accumulator for the movement of the separating element, it is in the hand to optimally adapt the flow rate of the reaching over the backwash guide to the filter element rinsing liquid to the circumstances, i. to be selected so that the best possible rinsing effect is achieved in adaptation to the type of filter medium. In particular, in relatively pressure-resistant filter elements, such as conical or cylindrical Spaltsiebrohrelementen, can be used in the hydraulic accumulator with high pressure level and thus high flow rates, whereby even stubborn dirt are safely removed from the filter surface.

In advantageous embodiments, the further fluid chamber of the hydraulic accumulator for the backwashing process by means of a valve control device with a compressed gas source is connectable. In many cases, the use of compressed air can be particularly advantageous, for example when the Filter device is operated in conjunction with systems or facilities in which a compressed air supply is available.

Preferably, the further fluid chamber of the hydraulic accumulator for the backwashing process by means of a valve control device with a compressed gas source is connectable. In particularly advantageous embodiments, the arrangement is in this case made such that a purge gas tank arranged outside the filter housing is provided as the compressed gas source. Without impairing the compactness of the filter device, a correspondingly large, stored gas volume can be made available for respective backwashing processes by means of a tank which is preloaded, for example, with compressed air.

In a particularly advantageous manner, the valve control device can have a fast-opening valve in a purge gas line leading from the compressed gas source to the hydraulic accumulator. As a result of a very rapid pressurization, a greatly accelerated movement of the separating element of the hydraulic accumulator can be achieved, so that a pressure surge is generated for the backwashing process, through which even stubborn soiling can be removed from the filter surface.

As a valve opening very quickly, a pneumatically actuated diaphragm valve can advantageously be provided in the purge gas line. In particularly advantageous embodiments, hydraulic accumulator and backflushing, connected to each other, rotatably arranged in the filter housing and rotatable for adjusting movements between filtration operation and backwashing by means of a rotary drive. Such an arrangement makes possible a particularly simple and compact construction in that a drive, preferably in the form of an electric geared motor, is mounted on a free and easily accessible end of the hydraulic accumulator. by means of which the hydraulic accumulator is adjustable to rotational positions in which the backwash guide forms the fluid connection to the filter element to be cleaned. In a particularly advantageous manner may be provided as a hydraulic accumulator, a piston accumulator which is rotatable about the cylinder axis together with the arranged at a cylinder end backwash. Compared to other types of memory, such as diaphragm accumulator, spring, bellows or the like, the piston accumulator is characterized by a particularly robust design by a good ratio between size and Aufnehmbarer filling amount of purified fluid, the total displacement of the piston and thus approximately the total volume of Memory cylinder corresponds. In a particularly advantageous manner, the filter elements can be accommodated in each case in its own element chamber, which are arranged in the filter housing on a circular axis surrounding the cylinder axis concentric. With this concentric arrangement, the connection connection of the individual element chambers with the rotatable backflushing guide can be made particularly simple.

In a particularly advantageous manner, the hydraulic accumulator can be arranged between the element chambers surrounding it such that the fluid chambers of the hydraulic accumulator are located between the chamber connections of the element chambers located at the ends of the filter elements. Such an arrangement in which the hydraulic accumulator is integrated between the respective inlet and outlet of the element chambers, allows a particularly compact design of the overall device with a particularly advantageous ratio between the required height and achievable size of the usable filter area. In particularly advantageous embodiments, in the filter housing between the hydraulic accumulator and the surrounding element chambers forming the raw side during the filtration process, the filter inlet exhibiting input space and a separate, connected to the filter outlet, the clean side during the filtration process forming exit space available, of which the first room with the raw-side chamber connection and the second with the clean-side chamber connection of the element chambers located in the filtration operation are in communication. Advantageously, the arrangement can also be made such that in the filter housing is provided to the clean-side chamber connections of the element chambers overflow space, which is in communication with the output space and from the corresponding at a Filtrationsvorgang rotary position of the hydraulic accumulator whose first fluid chamber via an in the wall of the backwash guide located Auffüllbohrung can be filled with cleaned fluid.

On the other hand, in other rotational positions of the hydraulic accumulator, which correspond to the backwashing of an element chamber, the backwash guide is connected to the clean-side chamber connection of the element chamber to be backwashed, at the same time a backwash arm, which is rotatable together with the hydraulic accumulator, at the end of the cylinder of the hydraulic accumulator opposite the backwash guide, for the outflow of a backwashing amount, connects the raw-side chamber connection of the element chamber to be backwashed to a backwash line.

In the fluid connection between the backwash and the backwash line, a motor-operated backwash valve can be arranged, which is preferably a ball valve, which can be rotatable by means of a pneumatic drive. The invention with reference to embodiments shown in the drawings will be explained in detail. Show it:

Fig. 1A to 1 C schematically simplified drawn, perspective

 Oblique views of the filter device according to the invention in an embodiment with two or four or six filter element chambers;

Fig. 2 and 3 with respect to Figure 1 drawn on a larger scale, perspective oblique views of the embodiment with six filter element chambers, seen on the front or the back of the device.

Fig. 4 is a central longitudinal section of the embodiment of

 Fig. 2 and 3, wherein the operating state of the filtration operation is illustrated;

FIG. 5 shows a longitudinal section corresponding to FIG. 4, the operating state of the backwashing of the element chamber which is visible on the right side being illustrated; FIG.

Fig. 6 shows a comparison with Figs. 4 and 5 further enlarged drawn longitudinal section of the embodiments of the filter device associated Spülgastanks associated with functional components and

Fig. 7 a comparison with FIG. 6 further enlarged drawn

Longitudinal section of the flushing gas tank of Fig. 6 associated diaphragm valve. In FIG. 1, which in the subfigures 1A to 1 C respectively shows an overall view of the filter device according to the invention, a housing main part with 1, filter element chambers with 3 and a drive part with 5 are designated. An inlet provided at the main portion 1 for the supply of fluid to be purged is denoted by 7, and an outlet for purged fluid is denoted by 9. Fig. 1 also illustrates that the device according to the invention in the manner of a modular modular system for operation with a different number of filter elements can be formed. Thus, Fig. 1A shows an example with two filter element chambers 3, in each of which a filter element 1 1 (Figures 4 and 5) is receivable, while Figure 1 B is an example with four element chambers 3 and Fig. 1C is an example with six Element chambers 3 show. In each element chamber 3, a plurality of filter elements 1 1 may be provided, for example in the form of a so-called. Filter candle, as is the case in the present case.

2 and 3, the embodiment of the filter device with six element chambers 3 is shown, wherein in Fig. 2, the front side with the inlet 7 and the outlet 9 can be seen, while Fig. 3 shows the opposite back, at the a purge gas tank 13 is attached. On the purge gas tank 13, a diaphragm valve 15 is connected, which is shown in Fig. 7 in a single representation and is pneumatically actuated. In turn, a purge gas line 17 connects to the diaphragm valve 15, via which the device can be supplied with purge gas under pressure, which will be discussed in more detail with reference to FIGS. 4 to 6.

4 and 5 each show a longitudinal section of the device, wherein FIG. 4 shows the operating state of the filtration operation, while FIG. 5 shows the state in the backwashing of the filter element 11, which is in the element chambers shown on the right in FIG 3 is located. As can be seen most clearly in FIGS. 2 and 3, the element chambers 3 are arranged lying on a circular line in such a way that they interpose one between concentric surrounding hydraulic accumulator. The hydraulic accumulator is, as shown in FIGS. 4 and 5, formed by a piston accumulator 19. As can also be seen in FIGS. 4 and 5, in the housing main part 1 between the element chambers 3 and the piston accumulator 19 there is formed an entry space 21, which is in communication with the housing inlet 7, and an exit space 23 which communicates with the outlet 9 of the housing Housing is connected. The input space 21 is connected to the bottom side chamber connection 25 of the element chambers 3 located in the filtration operation in FIGS. 4 and 5 at the bottom. The output space 23 is at the top in Figs. 4 and 5 with an overflow 27 in connection with which in turn the clean-side chamber connections 29 of the filtration element located in the element chambers 3 are in communication, as shown in FIG. 4 can be removed, the State of the filtration operation shows. Here, as indicated in Fig. 4 with dotted arrows 41, the unfiltered from the inlet chamber 21 through the chamber connections 25 in the element chambers 3 and flows through the filter elements 1 1 from outside to inside, from which the filtered fluid through the clean-side chamber connections 29th reaches the overflow 27. From there, the filtrate, as the arrows 43 show, flows to the exit space 23 and leaves it via the outlet 9.

The piston accumulator 19 is rotatable about its cylinder axis between input space 21 and output space 23, a sealed rotary bearing 31 being provided on a housing shoulder 33 which separates the input space 21 from the output space 23. Another, sealed pivot bearing 35 is located on a bottom part 37, which closes the housing on the bottom side. For setting the piston accumulator 29 to desired rotational positions of the piston accumulator 19 is coupled via a drive shaft 39 with the drive part 5, which is an electrical geared motor with integrated rotational position sensor. As in particular in the case of the rotational position of the piston feed shown in FIG. Chers 19 can be seen, this has at the top of the cylinder in the drawing on a backwash 45, starting from the cylinder chamber 47, projecting, to the clean-side chamber port 29 of the back-flushing element chamber 3, in which it is in the illustration of FIG the right side visible element chamber 3 acts. At the lower end of the piston accumulator 19, this has a Rückspülarm 49, which has a similar cantilevered course as the upper backwash 45, but extends from the raw-side chamber port 25 of the back-flushing element chamber 3 to a Rückspülausgang 51 for the discharge of backwash with entrained sludge , As indicated by the arrows 43, the backwash amount loaded with sludge passes through a backwash valve in the form of a ball valve 53, which is rotatable by a pneumatic drive 55, to a backwash line 57 and to an outlet flange 60.

During the filtration process, as illustrated in FIG. 4, the piston accumulator 19 is in a rotational position in which the backwash guide 45 is not arranged on a chamber connection 29 of an element chamber 3 to be backwashed. In this operating state, filtrate flows from the overflow space 27 into the cylinder chamber 47 of the piston accumulator 19 via a fill-up bore 46 (FIG. 5), which is formed in the wall of the backflushing guide 45 and is stepped to form a narrow inlet opening, and fills it Cylinder space 47, while the piston 59 of the piston accumulator 19 moves downward in the position shown in Fig. 4. In this filtration process, shown in FIG. 4

Rotary position of the located on the underside of the piston 59 cylinder chamber 48 is vented because the input 61 of a supply channel 63 for purge gas, which is visible only in Fig. 5, with a vent groove, not shown in the bottom part 37 of the housing in coverage. On the other hand, if for a backwash the piston accumulator 19 is in the rotational position shown in Fig. 5, the inlet 61 of the purge gas channel 63 with a purge gas line 65 in conjunction, see Fig. 6. For performing a backwash is by supplying compressed air over the Channel 63 of the piston 59 driven upward to produce from the located in the cylinder chamber 47 filtrate flow in the manner of a pressure surge, via the backwash guide 45 and the clean side chamber port 29 of the relevant element chamber 3, a filter element 1 1 from the inside out generates impulsive fluid flow and dissolves impurities, so that mud laden backwash quantity passes via the chamber connection 25 to the backwash output 51 and exits from there via the opened ball valve 53 and the backwash line 57. While in the illustrations of FIGS. 1 and 2, the outlet flange 60 is shown lying with the backwash line 57 respectively on the front side of the device, if necessary, the entire backwash output 51, including ball valve 53, backwash line 57 and flange 60 in any position on the housing. 1 be arranged because no drive connection between the rotatable piston accumulator 19 and the Rückspülausgang 51 is given.

Figs. 6 and 7 show details of the compressed gas supply. As already mentioned and shown in Fig. 3, a purge gas tank 13 is attached to the back of the device. Via a pressure line 67 with upstream pressure control valve 69 and a stopcock 71 of the purge gas tank 13 is charged with compressed air, which is supplied to the stopcock 71 from a compressed air line 73 ago, in which there is a check valve 75. In order to supply compressed air as a pressure surge via the purge gas line 65 to the piston accumulator 19 from the purge gas tank 13, a fast-opening valve in the form of the diaphragm valve 15 is provided at a port 77 of the purge gas tank 13, which is pneumatically actuated via a control line 79. The membrane valve 15 shown in more detail in FIG. 7 is connected via a connection sleeve 81 connected to the purge gas line 65. In Fig. 7, the diaphragm valve 15 is shown in the closed position, in which the membrane 83 is held by a prevailing in the located in the upper side in the diaphragm 83 control chamber 85 control pressure against the pressure prevailing at the terminal 77 pressure of the purge gas tank 13 in the closed position. When venting the control chamber 85, the diaphragm valve 15 opens quickly, so that by means of a compressed air pressure surge of the piston 59 of the piston accumulator 19 is moved abruptly for a backwashing.

Claims

P a n t a n s p r e c h e Filter device with a plurality of filter elements (1 1), which are accommodated in a filter housing (1) with a filter inlet (7) for fluid to be filtered and a filter outlet (9) for the filtered fluid, wherein during the filtration process at least one of the filter elements ( 1 1) for cleaning its effective filter surface by means of a backwashing (45, 49) is backwashed, which includes a pressure control device (19) for supporting the backwashing, characterized in that the pressure control device includes a hydraulic accumulator (19) having a fluid chamber (47) during the filtration process with an amount of cleaned fluid fillable and for a backwash via a backwash (45) with the clean side (29) of the filter element (1 1) to be cleaned off, and that a further fluid chamber (48) of the hydraulic accumulator (19) for a backwashing with a gas pressure can be acted upon by a d Adurch effected movement of the separating element (59) of the hydraulic accumulator (19) at least partially deliver the filling amount of the cleaned fluid for the backwashing process from the first fluid chamber (47). Filter device according to claim 1, characterized in that the further fluid chamber (48) of the hydraulic accumulator (19) for the backwashing process by means of a valve control device (15) with a compressed gas source (13) is connectable. Filter device according to claim 1 or 2, characterized in that as pressure gas source outside of the filter housing (1) arranged rinsing gas tank (13) is provided. 4. Filter device according to one of the preceding claims, characterized in that the valve control device in one of the Compressed gas source (13) to the hydraulic accumulator (19) leading purge gas line (65) has a fast-opening valve (15). 5. Filter device according to one of the preceding claims, characterized in that a pneumatically actuated diaphragm valve (1 5) in the purge gas line (65) is provided. 6. Filter device according to one of the preceding claims, characterized in that the hydraulic accumulator (19) and backwash guide (45) connected to each other, rotatably arranged in the filter housing (1) and for adjustment movements between filtration operation and backwashing by means of a rotary drive (5) are rotatable , 7. Filter device according to one of the preceding claims, characterized in that a piston accumulator (19) is provided as the hydraulic accumulator, which is rotatable together with the arranged at a cylinder end backwash guide (45) about the cylinder axis. 8. Filter device according to one of the preceding claims, characterized in that the filter elements (1 1) in each case a separate element chamber (3) can be accommodated, which are arranged in the filter housing (1) on a cylinder axis concentrically surrounding circular line. 9. Filter device according to one of the preceding claims, characterized in that the hydraulic accumulator (19) between the surrounding element chambers (3) is arranged such that the fluid chambers (47, 48) of the hydraulic accumulator (19) between the at the ends of the Filter elements (1 1) located chamber connections (25, 29) of the element chambers (3) are located. 10. Filter device according to one of the preceding claims, characterized in that in the filter housing (1) between the Hydrospei- Rather, (19) and the surrounding element chambers (3) form an inlet space (21) forming the raw side during the filtration process and having a filter inlet (7) and a separate outlet space connected to the filter outlet (9) and forming the clean side during the filtration process ( 23), of which the first chamber (21) with the raw-side chamber connection (29) and the second (47) with the clean-side chamber connection (29) of the element chambers (3) located in the filtration operation are in communication. 1 1. Filter device according to one of the preceding claims, characterized in that in the filter housing (1) to the clean side chamber connections (29) of the element chambers (3) subsequent overflow space (27) is provided, with the output space (23) in connection and from which the first fluid chamber (47) of the hydraulic accumulator (19) via a in the wall of the backwash (45) located Auffüllbohrung (46) can be filled with cleaned fluid. 12. Filter device according to one of the preceding claims, characterized in that in the backwashing of an element chamber (3) corresponding rotational positions of the hydraulic accumulator (19) the backwash (45) with the clean-side chamber connection (29) of the back-flushing element chamber (3) is connected and in that on the backwash guide (45) opposite end of the cylinder of the hydraulic accumulator (19) is arranged together with this rotatable backwash (49) for the outflow of a backwash the raw side chamber connection (25) of the back-flushing element chamber (3) with a backwash line (57) connects. 13. Filter device according to one of the preceding claims, characterized in that the backwash (49) with the backwash line (57) via a motor-operated backwash valve (71) is connectable. 1 . Filter device according to one of the preceding claims, characterized in that a backwash valve in the form of a ball valve (71) is provided.